
### Key Features Implemented:
1. **Query Engine**: SQL-like interface for data filtering and aggregation
2. **Stats Engine**: T-tests and causal impact analysis
3. **Viz Engine**: Customizable Plotly visualizations with dark theme
4. **PDF Generator**: Automated welcome PDF with QR code
5. **Footer System**: Consistent branding across all outputs
6. **Installation Welcome**: Custom ASCII art welcome message

### Usage Instructions:
1. Install the package: `pip install louati-analytics`
2. Import the engines in your Python script
3. Use SQL-like syntax for queries:
   ```python
   result = query_engine.execute_query("SELECT sales, region WHERE region='Europe'")